YUSART myusart;
u16 tdat=0;
u16 tflag=0;
void TIME4_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE); //时钟使能
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值 计数到5000为500ms
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值 10Khz的计数频率
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位
TIM_ITConfig( //使能或者失能指定的TIM中断
TIM4, //TIM2
TIM_IT_Update ,
ENABLE //使能
);
NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn; //TIM3中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //先占优先级0级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //从优先级3级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器
TIM_Cmd(TIM4, ENABLE); //使能TIMx外设
}
void TIM4_IRQHandler(void) //TIM3中断 1MS
{
u8 st;
if (TIM_GetITStatus(TIM4, TIM_IT_Update) != RESET) //检查指定的TIM中断发生与否:TIM 中断源
{
st= TIM_GetFlagStatus(TIM4, TIM_FLAG_Update);
if(st==SET)
{
TIM_ClearFlag(TIM4, TIM_FLAG_Update);
tdat++;
if(!(tdat&0x0F)) //16MS
{
tflag |= _bit(1);
}
if(myusart.timout>0)
{
if(--myusart.timout==0)
{
myusart.reflag=1; //收到一帧数据
}
}
}
TIM_ClearITPendingBit(TIM4, TIM_IT_Update ); //清除TIMx的中断待处理位:TIM 中断源
}
}